If you haven’t been playing Rockstar Games’ Red Dead Redemption 2 then seriously, you need to.

With so much to do, explore, hunt, and kill, RDR2 is the gift that keeps on giving, and one thing it’s definitely not short of is Easter eggs.

Credit: Rockstar Games

Players have already uncovered a tonne of Easter eggs hidden throughout the world, including the infamous Donkey Lady as well as Grand Theft Auto 5′s Michael, but this new secret might be hinting towards something very exciting…

The sleuths over on Reddit are wondering just what this message on one of the game’s barns actually means, and it’s believed it could be a reference to Undead Nightmare 2.

This could be amazingly cool – if true – but Undead Nightmare 2 isn’t the only theory behind the ‘Stay Out! Plague’ barn.

Some people believe the Easter egg could be a reference to The Walking Dead, with one user writing: “I thought it was a The Walking Dead reference/easter egg. I’m not sure they’re going to be doing the same type of DLC twice.

Credit: Rockstar Games

“Personally I enjoyed it immensely, and wouldn’t mind at all, but I think they will be doing something else this time around, but I guess only time will tell.”

Another added: “It’s a Walking Dead reference. On one of the episodes, they put zombies in an identical barn, and the tombstone nearby that barn in game is the same amount of zombies killed in that episode.”

It would make more sense to be a reference to a potential Undead Nightmare 2, seeing how successful the first one was.

Credit: Rockstar Games

If you didn’t play it, Red Dead Redemption: Undead Nightmare was the standalone expansion that added in a zombie horror-themed single-player campaign. There’s also two multiplayer modes, and a sprinkling of cosmetic additions to the environments and characters.